Flexing in forks

David Martin said:

Out for a meander[1] today. I took in a few uphills which have their
downside. heading down some of the steeper twistier hills I noticed that my
front fork seems to flex rather a lot under braking. Of the order of 1-2
inches.

The word on r.b.t is that a lot of fork flexing is an optical illusion
as your head wobbles about. The steerer tube does bend inside the head
tube, which translates to quite a big movement at the tips (and this
bending action is also what wears out headsets).

Zog The Undeniable said:

David Martin said:

Out for a meander[1] today. I took in a few uphills which have their
downside. heading down some of the steeper twistier hills I noticed
that my front fork seems to flex rather a lot under braking. Of the
order of 1-2 inches.

The word on r.b.t is that a lot of fork flexing is an optical illusion
as your head wobbles about. The steerer tube does bend inside the
head tube, which translates to quite a big movement at the tips (and
this
bending action is also what wears out headsets).

I when descending, if I need to brake I am certainly not looking at my 531
or Columbus SLX forks. I can only start to imagine what the OP means about
his percieved flex, does the hub appear to move 1-2 inches back ? If mine
did the tyre would hit the downtube, it doesn't.

To the OP is there a problem by the way ?

in message <[email hidden]>, David Martin

(') said:

Out for a meander[1] today. I took in a few uphills which have their
downside. heading down some of the steeper twistier hills I noticed
that my front fork seems to flex rather a lot under braking. Of the
order of 1-2 inches.

This is a fork that is probably 531 (badged 653), not in a cast fork
crown. I know there is some play in the headset bearing but surely not
that much?

No, definitely not that much. Investigate, something may be cracked. If
the play is in the bearing you need to get the bearing sorted.

Quoted message said:

I'd seen on the map but never ridden, especially as it is an
alternative route to using fast A roads. Went out to see the Beech
Hedge at Meiklour (300 years old, 100ft high and 1/3 mile long) and
back via Perth.

It's amazing, that hedge, isn't it?

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Morning had broken. I found a rather battered tube of Araldite
resin in the bottom of the toolbag.

David Martin said:

Out for a meander[1] today. I took in a few uphills which have their
downside. heading down some of the steeper twistier hills I noticed that my
front fork seems to flex rather a lot under braking. Of the order of 1-2
inches.

This is a fork that is probably 531 (badged 653), not in a cast fork crown.
I know there is some play in the headset bearing but surely not that much?

..d

[1] I'd been looking at the map and decided to try a bunch of minor roads
I'd seen on the map but never ridden, especially as it is an alternative
route to using fast A roads. Went out to see the Beech Hedge at Meiklour
(300 years old, 100ft high and 1/3 mile long) and back via Perth. Found a
nice coffee shop at Quarrymill that wasn't quite open at quarter to ten but
they served me anyway.

I have noticed that this is a lot more apparent with straight bladed
forks. When I first got my Joe Waugh with straight forks it freaked me
out for a while. When the frame finally broke it wasnt there. In the end
it rusted through the chainstays from inside. It was a good bike though.
If The guy I bought it from had taken more care I might still be riding it.

Stan Cox

On 4/9/04 5:35 pm, in article
[email hidden], "Simon Brooke"

Quoted message said:

in message <[email hidden]>, David Martin

(') said:

Out for a meander[1] today. I took in a few uphills which have their
downside. heading down some of the steeper twistier hills I noticed
that my front fork seems to flex rather a lot under braking. Of the
order of 1-2 inches.

This is a fork that is probably 531 (badged 653), not in a cast fork
crown. I know there is some play in the headset bearing but surely not
that much?

No, definitely not that much. Investigate, something may be cracked. If
the play is in the bearing you need to get the bearing sorted.

OK, I'm probably exaggerating the distance. There definitely is some flex
and the bearing definitely needs to be sorted (one of the race supports is
cracked).

With it being a very short head tube (I am not the tallest of people) I
would expect that any play in the bearings would have more effect than on a
larger frame.

It's on the list of things to sort out over the winter, along with a
respray, possibly modifying bits of the frame (respace to 130mm), new
headset bearing, potentially new forks, potentially fit a triple. I do like
the look of the TA Vega cranks.

Quoted message said:

Quoted message said:

I'd seen on the map but never ridden, especially as it is an
alternative route to using fast A roads. Went out to see the Beech
Hedge at Meiklour (300 years old, 100ft high and 1/3 mile long) and
back via Perth.

It's amazing, that hedge, isn't it?

And to think that the guys who planted it never saw it grow (or so the story
goes that they planted the hedge and then went off to do battle at Culloden,
which is where they stayed.)

I didn't much care for the A93 though and spent as little time on it as
possible. A friend of mine had a very bad crash (car) there just before
christmas last year - the driver coming the other way crossed the road
coming round one of the bends far too fast and hit her head on. He was
killed outright. She suffered minor but persistent injuries. Fortunately her
two kids were completely unhurt (in good quality child restraints.)

The Quarrymill woodland park has a very nice coffee shop. Well worth adding
to the list of good places to stop.

...d

in message <[email hidden]>, David Martin

(') said:

It's on the list of things to sort out over the winter, along with a
respray, possibly modifying bits of the frame (respace to 130mm), new
headset bearing, potentially new forks, potentially fit a triple. I do
like the look of the TA Vega cranks.

I know. So do I... I was seriously debating getting a set for the Dolan.
And one of these days the Centaur chainset that's now on the Dolan
might just migrate to my Raleigh to make room for a new TA Vega on the
Dolan...

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; All in all you're just another nick in the ball
-- Think Droid